# -*-coding:utf-8 -*-
from multiprocessing import Process

def plus():
    print("------子进程1开始------")
    global g_num
    g_num += 50
    print("g_num is %d"%g_num)
    print("------子进程1结束------")

def minus():
    print("------子进程2开始------")
    global g_num
    g_num -= 50
    print("g_num is %d"%g_num)
    print("------子进程2结束------")

g_num = 100
if __name__ == "__main__":
    print("------主进程开始------")
    print("g_num is %d"%g_num)
    p1 = Process(target=plus)
    p2 = Process(target=minus)
    p1.start()
    p2.start()
    p1.join()
    p2.join()
    print("------主进程结束------")